Connecting and deflection element for pull strips in a pneumatic component

ABSTRACT

Connecting and deflecting element for pneumatic structural elements, comprising a hollow body ( 1 ) with two caps ( 5 ), and also comprising a compression member ( 2 ) between two joint elements ( 3 ) on which tension members ( 4, 11 ) are fastened. The tension members ( 4, 11 ) run around the hollow body ( 1 ) once in opposite helical directions and thus cross over at a crossover location ( 7 ) on a lateral line ( 6 ) located opposite the compression member ( 2 ). The connecting and deflecting element according to the invention is fitted at the crossover location ( 7 ). It comprises a base plate ( 8 ) which has a milled relief ( 9 ). The tension members ( 4, 11 ) are positioned in this milled relief such that they themselves no longer cross over, but the point of intersection of the lines of action of the tensile forces, illustrated by chain-dotted lines ( 10 ), essentially still coincides with the crossover location ( 7 ). For a cover, four threads ( 13 ) are provided in the base plate ( 8 ).

The present invention relates to a connecting and deflecting element fortension members in a pneumatic structural element according to thepreamble of Patent Claim 1.

In the case of pneumatic structural elements, for example according toWO 01/73245, the tensile loads which occur are transmitted to thepneumatic structural element from a joint element by tension members. Atleast two tension members are to be provided here, these, starting fromthe two joint elements of the pneumatic structural element, beingpositioned in opposite helical directions around the pneumaticstructural element and being pulled tight. In the case of two tensionmembers, these cross one another at one location; if, however, fourtension members are provided, then, depending on the configuration ofthe wraparound angles and the number of joints provided, at least threecrossover locations are possible.

The positions of the abovementioned crossover locations aremathematically easy to determine. Technical compliance with themathematical prediction, however, depends, not least, on the care takenin the manual work carried out when constructing and setting up such apneumatic structural element. In addition, in particular when thetension members are configured as steel cables, the crossover locationsare the cause of defects in the form of the outer skin of the pneumaticstructural element.

The object of the present invention is to provide a connecting anddeflecting element of the abovementioned type which makes it possible toovercome the cited disadvantages and which, moreover, can be producedcost-effectively as a mass-produced item.

The solution to the set object is represented, in respect of itsfundamental features, in the characterizing part of Patent Claim 1 and,in respect of further advantageous embodiments, in the subsequent patentclaims.

The subject-matter of the invention with a number of exemplaryembodiments and variants thereof will be explained in more detail withreference to the attached drawing, in which:

FIG. 1 shows a pneumatic structural element according to the prior art,

FIG. 2 shows a first exemplary embodiment of a connecting and deflectingelement,

FIG. 3 shows an isometric illustration of the first exemplary embodimentof a connecting and deflecting element,

FIG. 4 shows a cross section of the first exemplary embodiment,

FIG. 5 shows an isometric illustration of a second exemplary embodimentof a connecting and deflecting element,

FIG. 6 shows a cross section of the second exemplary embodiment,

FIG. 7 shows a cross section of a variant of the second exemplaryembodiment,

FIG. 8 shows a third exemplary embodiment,

FIG. 9 shows a scheme for producing variants of the three exemplaryembodiments,

FIG. 10 shows an isometric illustration of a first variant of the secondexemplary embodiment,

FIG. 11 shows an isometric illustration of a variant of the firstexemplary embodiment,

FIG. 12 shows an isometric illustration of a second variant of thesecond exemplary embodiment, and

FIG. 13 shows a cross section of the second variant of the secondexemplary embodiment.

FIG. 1 is an isometric illustration of a pneumatic structural elementaccording to the prior art. It is constructed from an essentiallycylindrical gas-tight hollow body 1 with two caps 5. A compressionmember 2 is clamped in between two joint elements 3. Also fastened onsaid compression member are two tension members 4, which are guided inopposite helical directions around the hollow body 1 and butt tightlyagainst the same. The tension members 4 cross over one another on alateral line 6, which runs opposite the compression member 2, at acrossover location 7 halfway along the cylindrical hollow body 1.

FIGS. 2 and 3 illustrate a first exemplary embodiment of a connectingand deflecting element according to the invention; FIG. 2 shows a planview and FIG. 3 shows an isometric illustration. A plate 8, which isbasically curved such that it butts smoothly against a hollow body 1with a certain diameter, has a milled relief 9. Two tension members 4 inthe form of cables 11 are positioned in the milled relief 9 and abuttangentially there without buckling. Two chain-dotted lines 10 indicatethe lines of action of the cables 11. The lines of action 10 intersectone another at the crossover location 7 and indicate the course taken bythe tensile forces running through the cables 11. The cables 11themselves no longer cross over.

Four threads 13 are provided for a cover (not illustrated), which may bescrewed, as a variant, onto the connecting and deflecting element.

In the cross section AA according to FIG. 4, four cables 11 areprovided, in each case two cables located one beside the other form atension member 4. A cover 14 is provided here in order to force thecables 11 to be guided one beside the other. The cover 14 may bedesigned such that it clamps the cables 11 simultaneously or else is acarrier of a clamping device—which is known but is not illustrated here.

Instead of being produced by milling, the completed plate 8—includingthe shaping element referred to as the milled relief 9—may be producedby stamping, drop-forging, extrusion or a similar, that is to saygenerally by a non-cutting, shaping method, which makes it possible toreduce the piece costs to a considerable extent.

FIGS. 5 and 6 are illustrations of a second exemplary embodiment of theconnecting and deflecting element; FIG. 5 is an isometric illustrationand FIG. 6 is a section BB. This connecting and deflecting element isconfigured as a hollow body 15 with a curvature which matches thepneumatic structural element of the selected size. The clear height ofthe hollow body 15, this being provided transversely to the cables 11,is dimensioned such that it corresponds to the diameter of the cables 11such that these can be drawn in without being clamped. The cables 11 canbe subsequently clamped in place by deformation of the flat hollow body15 or by wedging.

A variant of the second exemplary embodiment according to FIG. 7,illustrated in a section analogous to FIG. 6, is provided foraccommodating four or more cables 11. Either a tension member 4 thenlikewise comprises a plurality of cables 11 or it is necessary touncross crossovers of more than two tension members 4.

The hollow bodies 15 according to FIGS. 5 to 7 may be shaped fromtubular material, either by shaping on an individual basis and/or byextrusion, the latter, in particular, relating to FIGS. 12 and 13.

FIG. 8 shows a third exemplary embodiment of a connecting and deflectingelement according to the invention. A connecting and deflecting element24 constructed from two essentially identical parts 22, 23 is heldtogether by a schematically illustrated screw connection 25. The entireaxial projection of the tensile forces thus runs through the screwconnection, which is of correspondingly tension-resistant configuration,for which means and materials are known per se. The cables 11 arefastened in anchors 26 with an outer contour in the form of sphericalsegments. These are located in correspondingly shaped sockets 27, withthe result that the fastening locations of the cables 11 are notsubjected to the action of any bending moments. Lead-outs 28 for thecables 11 are of correspondingly conical configuration. This makes itpossible to allow for slight deviations from the desired geometry of thepneumatic structural element.

The connecting and deflecting element 24 may be configured, in a manneranalogous to that of FIG. 4, as a curved plate or, in a manner analogousto that of FIG. 10, as part of the compression member 2. In thelast-mentioned case, the screw connection 25 is purely for adjustingpurposes or can also be dispensed with altogether.

Of course, it is also possible for the connecting and deflecting element24 to be configured for more than four cables 11, irrespective ofwhether the cables are then to be arranged in one or more planes.

The connecting and deflecting element 24 is used, in particular,wherever numerous tension members are provided for a pneumaticstructural element, for example in the case of a pneumatic structuralelement which is used as a column and subjected to axial loading. It maybe advantageous here for the tension members 4 to be subdivided and forthe parts to be joined together by connecting and deflecting elements24. This facilitates, furthermore, a modular construction of pneumaticstructural elements.

If a pneumatic structural element has two or more compression members 2,and if each compression member 2, as illustrated in FIG. 1, is assignedtwo tension members 4, this results in crossover locations 7 on orbeneath the compression members. In order to avoid this, variants of theconnecting and deflecting element 8, 15 and 24 are provided.

FIGS. 9 a and b show, schematically, how a connecting and deflectingelement 8, 15, 24 is divided along its centre line 31, parallel to thecompression member, with the result that two functional halves 18, 30are produced. These functional halves 18, 30 may then be joined togetherin various ways to form further variants of connecting and deflectingelements which avoid crossover locations 7 on a compression member 2.

In a first variant (FIG. 9 c), the functional halves 18, 30 are fastenedon a base plate 32 such that an interspace for the compression member 2is produced. A cover 14 may likewise be fitted, as a result of which thecompression member is enclosed by the connecting and deflecting element.Fitting the two functional halves 18, 30 only on the cover 14 and usingno base plate 32 is likewise in accordance with the invention. A secondvariant (FIG. 9 d) is based on the practice of introducing between thetwo functional halves 18, 30 a central part 21 which can be subjected tocompressive loading, is fitted between pieces 20 of the compressionmember 2 and thus forms part of the compression member.

In a third variant (FIG. 9 e), the functional halves 18, 30 are providedwith comb-like protuberances 17 and the compression member 2 is providedwith grooves 16 matching these protuberances 17. The functional halves18, 30 can then be pushed into the grooves 16 and positioned. Theoperations of providing the protuberance 17 on the compression member 2and the groove 16 on the functional halves 18, 30 are likewise inaccordance with the invention.

FIGS. 10 to 12 show isometric illustrations of connecting and deflectingelements which correspond to the three variants in FIG. 9.

The connecting and deflecting element illustrated in FIG. 10 ispositioned over the compression member 2, with the result that in eachcase one hollow body 18 butts laterally against the compression member2. The hollow bodies 18 may be set up for accommodating in each case oneor more cables 11.

The connecting and deflecting element in FIG. 11 is set up foraccommodating in each case one or more cables 11 on each side of thecompression member 2. It is further designed such that it can beinserted between two pieces 20 of the compression member 2; in otherwords, its central part 21 itself forms part of the compression member.The parts 20, 21 of the compression member 2 can be forced intoalignment by mechanical means which are known per se.

The compression member 2 in FIG. 12 contains a groove 16 on each side,these grooves serving for accommodating protuberances 17 which areintegrally formed on flat hollow bodies 18. The hollow bodies 18 may beconfigured such that they are suitable for one or more cables 11.

FIG. 13 is a sectional illustration DD of FIG. 12. The hollow body 18with its protuberance 17 has been formed by virtue of the tubularcomponent being shaped, and has been pushed into the groove 16 of thecompression member 2.

1. Connecting and deflecting element for tension members (4) ofpneumatic structural elements which comprise a cylindrical, gas-tighthollow body (1) with two caps (5), and also comprise a compressionmember (2) between two joint elements (3) and tension members (4) whichare fastened at the ends of the compression member (2), characterized inthat means are provided in order to fit at least two tension members (4)such that a crossover location of these very tension members (4) iseliminated, but the lines of action of the tensile forces continue tointersect one another essentially at the same crossover location (7). 2.Connecting and deflecting element according to Patent claim 1,characterized in that it is formed such that the tension members (4) arelocated essentially one beside the other in one plane in the connectingand deflecting element.
 3. Connecting and deflecting element accordingto Patent claim 1, characterized in that it is formed such that thetension members (4) are located essentially one above the other in anumber of planes in the connecting and deflecting element.
 4. Connectingand deflecting element according to Patent claim 1, characterized inthat it is curved such that it butts flush against the cylindrical shapeof the hollow body (1).
 5. Connecting and deflecting element accordingto Patent claims 2, 3 and 4, characterized in that it is set up fortension members (4) which comprise at least two cables (11). 6.Connecting and deflecting element according to either of Patent claims 2and 3 and Patent claim 4, characterized in that it is set up for tensionmembers (4) which comprise at least two cables (11).
 7. Connecting anddeflecting element according to Patent claim 5 or 6, characterized inthat it comprises a plate (8) which has a milled relief (9) for thetension members (4).
 8. Connecting and deflecting element according toPatent claim 7, characterized in that it is produced by a non-cuttingshaping method.
 9. Connecting and deflecting element according to Patentclaim 5 or 6, characterized in that it is configured as a hollow body(15).
 10. Connecting and deflecting element according to Patent claim 5or 6, characterized in that it is constructed from two essentiallyidentical parts (22, 23), in which case the parts (22, 23) each have atleast two sockets (27) on one side, the parts (22, 23) have, per socket(27), a conical lead-out (28) which runs from the socket (27) to theopposite side, spherical-segment anchors, which fit flush in the sockets(27), are fastened at the ends of the tension members (4), the tensionmembers (4) are drawn through the lead-outs (28) from the sockets (27),and the anchors (26) abut with sliding action in the sockets (27), thiscounteracting the production of bending moments at the fasteninglocations of the tension members (4) under tensile loading, the parts(22, 23) are joined together by a screw connection (25), which can besubjected to tensile loading, such that the sockets (27) rest on oneanother, and the parts (22, 23) form a connecting and deflecting elementwith one another.
 11. Connecting and deflecting element according to oneof Patent claims 7 to 10, characterized in that it is divided into twoessentially identical functional halves (30) along the centre line (31)parallel to the compression member (2), each of the functional halves(30) deflecting at least one tension member (4) and being fitted on thecompression member (2).
 12. Connecting and deflecting element accordingto Patent claim 11, characterized in that the two functional halves (30)are fastened on a plate (8) so as to produce an interspace for thecompression member (2), and a second plate (14) may be fastened as acover, with the result that the compression member (2) is enclosed. 13.Connecting and deflecting element according to Patent claim 11,characterized in that introduced between the two functional halves (30)is a workpiece which can be subjected to compressive loading and canconnect two pieces (20) of a compression member (2).
 14. Connecting anddeflecting element according to Patent claim 11, characterized in thatone of the parts (2, 30) has a comb-like protuberance (17) and the otherhas a matching groove (16), and the functional halves (30) are thusfastened on the compression member (2) by the protuberance (17) beingpushed into the groove (16) and positioned.
 15. Connecting anddeflecting element according to either of Patent claims 7 and 10,characterized in that it consists of a material which can be subjectedto compressive loading and it can be fitted between two pieces (20) of acompression member (2).